We have a tons of daily data driven subscriptions. Sometimes these subscriptions delivery fail due to even a single invalid email address (terminated employee). My question is there any way to create a parameter/code/expression that let's subscriptions to be distributed to users by skipping invalid email addresses?
Based on your comment response I believe I have a solution. You will need to add some error checking in your where clause to filter out anybody with erroneous or NULL emails. Alternatively, you could have a case statement that tries to detect and correct bad emails and replace NULLS with a junk local email address.
SSRS won't fail if it can't deliver the email but apparently it will fail if you don't have an email in your dataset for data driven subscription. It's going to be up to you to make sure this doesn't happen!